The present invention relates to a gas laser with high-frequency excitation, wherein the laser comprises a tube which is disposed in an electrically grounded metal housing, and wherein the laser has two electrodes for excitation by a high-frequency generator, and wherein the electrodes extend along the laser tube in diametrically opposite relation, one of the electrodes being electrically grounded while the other electrode is connected to a high-frequency feed line which contains a filter circuit with adjustable inductance and capacitance to adapt the impedance of the laser to that of the high-frequency generator.
In the following text, the customary abbreviations "HF" and "LC circuit" are used, respectively, for "high-frequency" and for "filter circuit".
A continuous HF-excited waveguide CO.sub.2 laser wtih high-frequency tunability and high output power has been described in the dissertation by G. Merkle of the Institute for Plasma Research of the University of Stuttgart, January 1983. According thereto, the LC circuit serves to make the imaginary (reactance) component of the laser impedance as nearly as possible equal to zero and to match the real component (resistance) to the internal resistance of the HF generator.